$('#password').focusin(function(){
    //密码框选中
    $('.login-box').addClass('up');
}).focusout(function(){
    //密码框非选中
    $('.login-box').removeClass('up');
})

$(document).on('mousemove',function(e){
    // let 块级关键字
    let dw = $(document).width() / 10;
    let dh = $(document).height() / 18;
    let x = e.pageX / dw;
    let y = e.pageY / dh;
    $('.eye-ball').css({
        left:x,
        top:y
    })
})